[labnetwork] Metered chemical dispensing?

[Albert William (Bill) Flounders]

 Aaron,
We have implemented consumption monitoring and billing on several tools..
They are not simple - but they are increasingly necessary.
Efforts from both equipment engineering team and computer team required.
We have only implemented for most expensive items
e.g., DUV resist (>$4K/gallon), germane (>$13K/cylinder), and Pt ALD
precursor.

For gases - mfc is tied to monitoring system.
Voltage to mfc is related to flow setting, time that voltage is >0 defines
how long to integrate.
For ALD - pulse counter added to ALD pulsing valve; charge per pulse
defined on estimated delivery volume.
For photoresist dispense, pulse counter added to resist flow control valve;
volume of resist dispensed per actuation
is estimated and charge per pulse defined.

Integrating these with the Laboratory Management System (LMS) was non
trivial.
Linkage of the monitoring system to the LMS is what enables the tracked
consumption to be
associated with the researcher who had the tool enabled for that run - and
provides automated billing.

Equipment and Facilities Manager may discuss with you offline.
He presented summary of system at UGIM 2014 or 2016.

Bill Flounders
UC Berkeley

On Tue, Dec 21, 2021 at 1:14 PM Aaron Hryciw <ahryciw at ualberta.ca> wrote:

> Hi all,
>
> In our open-access cleanroom, we provide common chemicals "free of
> charge", in the sense that there is no additional charge to use them apart
> from the tool time (e.g., hourly rate for wet deck login).  This includes
> such chemicals as acetone, IPA, photoresist developers, standard metal wet
> etchants, KOH, etc.; the cost of supplying the chemical is (at least in
> principle) wrapped up into the tool rate.  I believe that this is a fairly
> standard approach among cleanrooms in academic settings.
>
> A shortcoming of this approach is that high-volume chemical users are
> being charged the same as low-volume chemical users; there is also no
> (financial) incentive for users to limit their chemical usage to just the
> volume they need.  We are therefore looking into ways in which we can
> capture the actual volume of chemicals used by each user, at least for some
> high-value and/or high-volume chemicals, such that billing for
> chemical usage can be applied more fairly.  As global supply chain issues
> have increased the cost of chemicals, this is becoming even more important.
>
> Ideally, the method of capturing usage should be largely automated (e.g.,
> not just a physical chemical use logbook at each wet deck), such that it
> does not take a lot of staff bandwidth to administrate, and should not rely
> on the honour system only (e.g., logging usage of a material in our lab
> management software), to ensure compliance.
>
> One approach we have been considering is having some kind of metered
> chemical dispensing.  For instance, the piranha wet deck would be plumbed
> with dispensers (e.g., chemical-compatible metering pumps) for sulfuric
> acid and hydrogen peroxide, perhaps drawing from large drums of the stock
> chemicals housed remotely (e.g., in a subfab or service chase).  A
> qualified user would login to the dispenser (via our lab
> management software), dispense the required volumes of the chemicals,
> logout, and the volume used would be tracked and automatically logged to
> their account.
>
> I expect that such a scheme is not as simple as it seems, and that there
> are probably a host of engineering, software, and other logistical problems
> that would need to be solved to implement this safely and effectively, at
> least if a turnkey solution for this does not already exist.  Has anyone
> implemented anything like this in their own cleanroom?  Or is this a
> horribly over-engineered solution to a relatively minor problem?  I'd be
> very interested in hearing how others have dealt with the problem of
> charging users fairly for chemical usage.
>
> Cheers,
>
>  – Aaron
>
>
>
>
> Aaron Hryciw, PhD, PEng
>
> Fabrication Group Manager
>
> University of Alberta - nanoFAB
>
> W1-060 ECERF Building
>
> 9107 - 116 Street
>
> Edmonton, Alberta
>
> Canada T6G 2V4 Ph: 780-940-7938
> www.nanofab.ualberta.ca
>
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